The present application relates to scissors-action tools, and in particular to such a tool in which the blades are normally able to open to a restricted angle during use, and in which a simple adjustment permits the blades to be opened to a greater angle than normal.
Berg, et al., U.S. Pat. No. 5,745,997 discloses scissors including folding handles. A spring urges scissors blades apart from each other to a position of readiness for a cutting stroke so that it is unnecessary to include a loop in the handles of the scissors, and the scissors can therefore be folded to a relatively small size when not in use. The scissors include rockers that prevent the blades from opening beyond an angle at which the handles can be manipulated easily, but this angle is less than 90 degrees and does not expose the entire edge of each blade to be resharpened, so long as the blades are held together by their pivot joint. With the scissors blades held to a limited angle, however, the handles can be folded by overcoming the force of a spring pressing on a cam to keep each handle extended.
Berg et al. also disclose scissors with non-folding handles that can be moved to a stowed position in the handle of a folding multipurpose hand tool. In such scissors a rocker can be rotated to a position providing clearance to open the scissors blades to about 90 degrees to facilitate resharpening.
Hayden, U.S. Pat. No. 1,296,660 shows scissors including a thumbscrew attached to one handle and adjustable to limit the blades to being opened to an acute angle or to allow them to be opened to at least 90 degrees.
Frazer, U.S. Pat. No. 6,282,997 discloses small scissors included in a folding multipurpose tool. The blades of the scissors are urged apart from each other by a spring which has an end engaged in a slot defined in one of the handles. The slot limits the angle to which the blades can be opened apart from each other during normal use, but the end of the spring can be removed from the slot to permit the blades to be opened farther, to an angle which provides access to the edges of the scissors to permit them to be sharpened readily.
What is desired, then, is a scissors-action tool in which blades or pivoted jaws are urged open by a spring and normally are limited to a predetermined blade-separation angle, but in which a blade-separation limiting element can be moved to a second position, permitting the blades to be opened to a greater angle to facilitate maintenance of the tool such as resharpening cutting portions of scissors blades or shaping gripping faces of pliers jaws.